Process for breaking petroleum emulsions



Patented Apr. 21, 1936 PROCESS FOR BREAKING PETROLEUM:

EMULSIONS 1 Melvin De Groote, St. Louis, and Bernhard Keiser and Arthur F. Wirtel,

Webster Groves, Mo., as-

signors to Tretolite Company, Webster Groves, Mo., a corporation of Missouri No Drawing. Original application December 31, 1934, Serial No. 760,033. Divided and this ap-- plication December 6, 1935, Serial No. 53,268

- 7 Claims;

This invention relates to the treatment of emulsions of mineral oil and water, such as petroleum emulsions, for the purpose of separating the oil from the water.

Petroleum emulsions are of the water-in-oil type, and comprise fine droplets of naturallyoccurring waters or brines, dispersed in a more or less permanent state throughout the oil which constitutes the continuous phase of the emulsion.

10 They are obtained from producing wells and from the bottom of oil storage tanks, and are commonly referred to as cut oil, roily oil, emulsified oil and "bottom settlings.

The object of our invention is to provide a novel and inexpensive process for separating emulsions of the character referred to into their component parts of oil and water or brine.

Briefly described, our process consists in subjecting a petroleum emulsion of the water-in-oil 20 type to the action of a treating agent or demulsifying agent of the kind hereinafter described, thereby causing the emulsion to break down and separate into its component parts of oil and water or brine, when the emulsion is permitted to remain in a quiescent state after treatment, or is subjected to other equivalent separatory procedures, our present application being a division of our pending application Serial No. 760,033, filed December 31, 1934. 1

The treating agent used in our process consists of an unpolymerized keto fatty body or bodies. It is well known that fatty acids or fatty bodies can be subjected to chemical treatment so as to yield keto fatty acids, that is, fatty acids in which a ketonic group (a carbonyl group) is present. One example is the conversion of ricinoleic acid into ketohydroxystearic acid. (See Lewkowitsch Chemical Technology of Oils, Fats and Waxes, 6th edition, volume 1, page 242.) In a general way, the manufacture of such ketonic acids is dependent upon the treatment of an unsaturated fatty body or fatty acid,'such as ricinoleic acid, oleic acid, or the like, with a halogen, such as bromine, so as to form a. halogen addition product, for example, ricinoleic acid dibromide, which is then converted into ricinstearolic acid. Ricinstearolic acid, on treatment with sulfuric acid, yields ketohydroxystearic acid.

. In our co-pending applications for patent Serial No. 760,031, filed December 31, 1934, we have disclosed the use of poly keto fatty acids or the salts or esters thereof for breaking oil field emulsions.

In a general manner we have found that fre-v quently the poly keto fatty acid bodies are more eflective for breaking the majority of emulsions than the unpolymerized keto fatty acid bodies. This is true to the same general extent that. broadly speaking, polyricinoleic acids are more effective demulsifying reagents than ricinoleic acid. However, there are certain emulsions on 5 which the unpolymerized keto fatty acid bodies, which will be referred to more simply as keto fatty acid bodies", are more effective than the polymerized keto fatty acid bodies. The present process is concerned with the use of keto fatty 1o acid bodies in an unpolymerized state, in those instances where they are the most effective demulsifying agents.

As previously indicated, the method described in the Lewkowitsch reference for producing ketohydroxystearic acid bodies may be applied to various unsaturated acids and the like. Such process can be applied to the hydroxylated unsaturated materials obtained in the manner described in co-pending application for patent of Melvin De Groote and Bernhard Keiser, Serial No. 760,025, filed December 31, 1934. Said aforementioned application for patent discloses the oxidation of highly unsaturated fatty bodies having a relatively high iodine number, above 120, for example, so as to produce unsaturated, 'hydroxylated fatty bodies.

In our co-pending application for patent Serial No. 760,031, filed December 31, 1934, we have described a new composition of matter consisting of the poly keto fatty acid bodies. These poly keto fatty acid bodies may be obtained by the esterification or polymerization or condensation of a keto fatty acid withanother fatty acid a molecule, which need not contain a ketone group.

In said aforementioned applicationfor patent describing these new compositions of matter, there is also disclosed a method for producing poly keto fatty acids directly without first forming the unpolymerized keto fatty acids. It would appear at least theoretically possible to decompose such poly keto fatty acid bodies and perhaps separate from the resultant mixture unpolymerized keto fatty acid bodies. Thus far, however, we have been unable to accomplish this hydro ysis and 4: separation, but this is immaterial, because the keto fatty acids may be produced in the manner previously described. y

We are fully aware that migration may take place in a fatty molecule. For instance, that the formation of stearolactone from hydroxystearic acid appears to depend on the migration of the alcoholiform hydroxyl. We are also aware, that in the case of thecommon non-fatty ketbnic acid, aceto-acetic acid, thatcertain reactions ar zation is conducted with care.

We believe that this or a comparable change. may

take place in these ketonic fatty acids or 'bodies previously described. Possibly in regard to some reactions employed in identification, these keto" acids or salts or esters thereof act more as if they were aldehydic acids or esters or salts thereof. In other words, if these ketonic acid bodies are to be used in a mixture where aldehydic acids would be incompatible, it is also likely that these ketonic acids or their salts or their esters may be incompatible, for' the reason that they really may be aldehydic acid bodies. It is to be noted that reagents of the kind employed for determining the presence of the carbonyl group in ketones also usually detect the presence of the carbonyl group in aldehydes. It is to be understood that in the claims where the products are characterized by the presence of ketonic radical, that such acids might ultimately prove to be aldehydic acids, or at least convertible under certain con-'- ditions of use, or else under certain conditions of identification, possibly they become converted into aldehydic acids, and it is not intended that the word ketonic or keto be interpreted as excluding the meaning of aldehydic. in the sense previously described or discussed, 1. e., that both have the carbonyl (C) radical present, and their ultimate composition in carbon atoms, hydrogen atoms, and oxygen atoms, is identical.

It is understood, of course, that these keto fatty acids or their esters may be converted into salts or into esters inthe manner generally employed for the manufacture of salts and esters. However, it should be bornein mind that saponification of the kind which would decompose or destroy the carbonyl radical cannot be employed. In such instances where it is desirable to eliminate the residual acidity, it is best accomplished by means of a relatively weak base, such as triethanolamine, or it may be accomplished by means of a stronger base, such as ammonium hydroxide or caustic soda, provided the neutrali- In some instances it is desirable to mix an alcohol, particularly a polyhydric alcohol, such as, glycerine 'or ethylene glycol with a keto fatty acid body and then heat so as to eliminate the carboxylic hydrogen. In

any event, the ketonic bodies may be converted into any suitable form by meansv of conven onal reactions, provided thatthe material is not decomposed to destroy the carbonyl radical.

Our preferred reagent consists of keto hydroxy- The use of demulsifying agents consisting of various sulfo acids, or carboxy acids, or compounds having both a sulfo group and a carboxyl group, is well knownin the treatment of waterin-oil emulsions. Inthe use of conventional demulsifying agents it E the common practicetouse them not only in 'the form of acids, but also connection half esters, or ester salts, in case of-dibasic acids. The salts generally employed are the sodium salt, potassium salt, ammonium salt, calcium, magnesium, the triethanolamine salt, etc. The esters may be employed, such as the methyl ester, ethyl ester, propyl ester, butyl ester, amyl ester, hexyl ester, cetyl ester, etc. esters may be employed. What has been said in regard to the use of conventional demulsifying agents applies also to the materials employed as the demulsifying agent of our process, with the limitation that such materials are generally monobasic, although it is probable that dibasic acids, such as sulfoketostearic acid might be pre pared, and would prove to be a suitable demulsifying agent.

Conventional demulsifying agents employed in the treatment of oil field emulsions are used as such, or after dilution with any suitable solvent, such as water, petroleum hydrocarbons, such as gasoline, kerosene, stove oil, a coal tar product, such as benzene, toluene, xylene tar acid oil,

'cresol, anthracene oil, etc. Alcohols, particularly aliphatic alcohols, such as methyl alcohl, ethyl alcohol, denatured alcohol, propyl alcohol, butyl alcohol, hexyl alcohol, octyl alcohol, etc. may be employed as diluents. Miscellaneous solvents, such as pine oil, carbon tetrachloride, sulfur dioxide extract obtained in the refining of petroleum, etc. may be employed as diluents. Similarly, the material or-materials employed as the demulsifying agent of our process may be admixed with one or more of the solvents customarily used in with conventional demulsifying agents. Moreover, said material or materials 7 may be used alone or in admixture with other suitable well known classes of demulsifying agents, such as demulsifying agents of the modified fatty acid type, the ,petroleum sulfonate type, the alkylated sulfo-aromatic type, etc.

concentration employed. This same fact is true.

in regard to the material or materials employed as the demulsifying agent of our process.

As stated previously, it has been so common to use a conventional demulsifying agent derived from an acid in the form of the acid itself, or in the form of a salt, or in the form of anester,

that the expression acid body? is frequently employed to mean the acid itself, or an ester thereof,

or salt thereof. The word body is herein employed in-this same sense in conformity with its Aromatic or cyclic prior usage in the trade, and particularly in varlous patents of the prior art. Half salts and half esters are consideredas salts, and esters, respectively.

In practising our process a treating agent or demulsifying agent of the kind above described is brought into contact with or caused to act upon 5 the emulsion to be treated, in any of the various ways or by. any. ofthe' various apparatus now I generally used 'to resolve or break petroleum emulsions with a chemical reagent. 1 in the form of salts or esters, or half salts, or

Having thus described our invention what we Patent; is. a

, 1. A process for breaking a petroleum emulsion ofthe water-in-oil type, which consists in subjecting the emulsion 'tothe action of a demulsifying agent comprising an acid-free keto fatty acid ody.

claim as new and desire to secure by Letters 2. A process for breaking a petroleum emulsion of the water-in-oil type, which consists in subjecting the emulsion to the action of a'demulsify-' ing agent, comprising a keto fatty acid body in the form of a salt. y Y

3. A process for breaking a petroleum emulsion of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent, comprising a keto fatty acid body in the form oft-an ester.

4. A processfor breaking a petroleum emulsion of the water-in-oii type, which consists in subjecting the emulsion to the action of a demulsifying agent, comprising a keto fatty acid body in the form of a salt and derived from castor oil.

.Jecting the emulsion to the action of a demulsifying agent, comprising a ket'o fatty acid body in the form of an ester and derived from castor oil. 6. A process for breaking a petroleum emulsion of the water-inoil type, which consists in subjecting the emulsion to the action of an ester of ketohydroxystearic acid. I

7. A process for breaking a petroleum emulsion oi} the water-in-oil type, which consists in subjecting the emulsion to theaction of a salt of ketohydroxystearic acid. 7

MELVINDEGROOTE. 

